First, a bit of sadness: Heather Menzies, who plays the role of Louisa in 'The Sound of Music,' died of brain cancer on Dec. 24, 2017 in Ontario, Canada. The widow of actor Robert Urich, she had several film and TV roles after the classic movie.
AP/Twentieth Century Fox Home Entertainment

From left, Charmian Carr, as Liesl, Nicholas Hammond, as Friedrich, Julie Andrews, as Maria, Heather Menzies (back row) as Louisa, Duane Chase, as Kurt, and Angela Cartwright, as Brigitta, front row, from left, Kym Karath, as Gretl, and Debbie Turner, as Marta, in a scene from the film, 'The Sound of Music.'
AP

LOS ANGELES — Charmian Carr, the actress best known for sweetly portraying the eldest von Trapp daughter in Rogers & Hammerstein's "The Sound of Music," has died. She was 73.

She died Saturday of complications from a rare form of dementia in Los Angeles, Carr's spokesman, Harlan Boll, said.

At age 21, the actress portrayed Liesl von Trapp in the 1965 film musical "The Sound of Music." She famously performed the song "Sixteen Going on Seventeen."

After "The Sound of Music," Carr's only other major Hollywood role was starring with Anthony Perkins in the Stephen Sondheim television musical "Evening Primrose." She played a mysterious young woman who lived in a department store.

The actress later went on to write a pair of books about her "Sound of Music"experiences: "Forever Liesl" and "Letters to Liesl." She fully embraced audiences' reverence for the musical, frequently appearing at sing-a-long performances at the Hollywood Bowl.

Charmian Carr in an undated photo.(Photo: Eric Deutsch)

"I tell people that they should consider sing-a-long "Sound of Music" like going to a therapist," she told the AP before a 2005 appearance. "It's just a kind of therapy. They can move around. They can dance and talk back to the screen. They can skip their appointment with the shrink that week."

Carr went on to become an interior designer in Southern California. Her clients included Michael Jackson and "Sound of Music" screenwriter Ernest Lehman.

She was born in Chicago in 1942. Her mother was a vaudeville actress, and her father was a musician and orchestra leader. Her family moved to the San Fernando Valley when she was a child.

Carr is survived by her four siblings, her two children and four grandchildren.